Combined knob and permutation lock assembly for door latches

ABSTRACT

A permutation lock assembly incorporated into a door knob and latch mechanism mountable in the standard openings in conventional swinging doors, using conventional door latch hardware. Rotation of an outer dial in a first direction causes rotation of an inner dial which is visible through a window until a number on the inner dial appears at the center of the window. Upon rotation of the outer dial in an opposite direction until a number thereon is aligned with a center mark, the door is unlocked and may be readily opened. When the proper combination is known, the combination may be changed, within a few seconds, from one combination to another. Also incorporated is a clutch device in the external knob that permits the knob to turn in either direction when the door is locked and excessive force is applied, thus preventing damage to the assembly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a combined knob and permutation lockassembly for door latches and, more particularly, to a permutation lockassembly designed to fit conventional swinging doors to provide maximumsecurity without the need of a key which could be lost, stolen, orduplicated.

2. Description of the Prior Art

Conventional swinging doors typically include a combined knob and keylock assembly for activating the door latch. Such combined knob and keylock assemblies are readily installed in a door by drilling a singlecircular hole through the door and by drilling a second holeperpendicular to the first hole for the latch assembly. Thus, such aconstruction is readily securable to a door and provides a reasonabledegree of security, under normal circumstances.

The main problem with such a combined knob and key lock assembly is theneed for a key to unlock the door from the outside thereof. Such keyscan be lost, stolen, or duplicated, and the keyhole presents an openingfor tampering with the lock mechanism. If the key is lost or stolen, theprocedure for changing the combination typically requires theintervention of a skilled locksmith and the high cost associatedtherewith.

One common approach to solving the problem of lost keys for locks ingeneral is the use of a permutation-type lock assembly. With apermutation-type lock, keys may be eliminated, thereby eliminating theproblems associated with the loss thereof. However, whilepermutation-type locks are generally well known, they are not generallyknown for use in combination with a door knob to operate a door latch.

U.S. Pat. Nos. 724,774; 1,076,171; 1,217,802; 1,287,435; 1,554,270;1,816,575; and 2,836,052 disclose permutation lock assemblies for usewith a swinging door. However, all of such mechanisms have at least oneof several problems associated therewith. In some of these mechanisms,the entire lock assembly is external to the door where it isunattractive and readily available for tampering or destruction. Othersof said mechanisms require substantial modification to the normal doorapertures or the addition of separate and distinct locking elementsdifferent from the conventional door latch. Heretofore, it has beenunknown to provide a combined knob and permutation lock assemblydesigned to fit conventional swinging doors without any modificationthereto for use with conventional door latches to provide maximumsecurity without the need of a key which could be lost, stolen, orduplicated.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a combined knoband permutation lock assembly for door latches which is designed to fitconventional swinging doors to provide maximum security without the needof a key which could be lost, stolen, or duplicated. With the presentassembly, there is no need to prepare the door beyond the normallydrilled openings for conventional hardware. Once installed, the externaldoor knob was positioned adjacent thereto a coaxial cone which can berotated first in one direction and then in another direction to dial adesired combination. A minimum of 3,540 combinations are available.Furthermore, the present assembly permits the operator, when the propercombination is known, to change, within a matter of seconds, from onecombination to another, thereby eliminating the expensive re-keyingprocess normally associated with key-activated locks.

When the present door is locked, the knob can not be turned and the doorlatch will not retract. On the other hand, a clutch device in theexternal knob permits the knob to turn in either direction when the dooris locked and excessive force is applied thereto, thus preventing damageto the present assembly.

The present assembly offers outstanding visibility of the dialcharacters with the main dial on a two-dial mechanism controlling asecondary, hidden dial. Thus, the door can be programed to open veryrapidly with the use of one hand rotating the main dial in onedirection, which rotates the inner dial, which is visible through amagnifying lens. Then, by rotating the main dial in the other directionto the proper number, the door is unlocked. Locking the door knob isachieved by simply rotating through an angle of 90° a dial mountedwithin the internal knob.

Briefly, the present combined knob and permutation lock assembly fordoor latches comprises coaxial external and internal knobs mounted forrotation on opposite sides of a door; a composite shaft extendingcoaxially between the door knobs for rotation therewith, the shaftengaging and activating the door latch upon rotation thereof by eitherof the knobs; a sleeve mounted on the shaft for axial movement onlyrelative thereto, the sleeve having a diagonal slot therein andincluding a radially extending key; a pin mounted within the shaft andbeing movable axially relative thereto, perpendicular to the axis of theshaft, through a hole therein, into and out of the slot in the sleeve,the shaft being rotatable independently of the sleeve to activate thedoor latch when the pin is withdrawn from the slot in the sleeve,rotation of the shaft causing axial movement of the sleeve when the pinis extending into the slot therein; means for biasing the pin out of theslot in the sleeve; cam means manually operable from a point adjacentthe internal knob for moving the pin into the slot in the sleeve tothereby lock the door; first and second coplanar locking rings mountedcoaxially with the shaft, the locking rings having first and secondslots therein, respectively, which are alignable with the sleeve key,the locking rings preventing axial movement of the sleeve and therebypreventing rotation of the shaft and activation of the door latch,except when both the first and second slots are aligned with the sleevekey; and means mounted coaxially with and adjacent the external doorknob and operatively connected to the first and second locking rings forindependently moving the locking rings to unlock the assembly. The meansfor moving the locking rings comprises outer and inner concentric dialsmounted adjacent the external door knob and having indicia on theoutwardly directed faces thereof; means interconnecting the dials forrotation of the inner dial with the outer dial in a first rotarydirection only; and means operatively connecting the first and secondlocking rings to the outer and inner dials, respectively, for rotationtherewith, the outer dial being rotatable in the first direction toalign the inner dial and the slot in the second locking ring with thesleeve key, the outer dial then being rotatable in an opposite rotarydirection to align the slot in the first locking ring with the sleevekey, the inner dial and the second locking ring remaining stationaryduring rotation of the outer dial and the first locking ring in theopposite direction.

OBJECTS

It is therefore an object of the present invention to provide a combinedknob and permutation lock assembly for door latches.

It is a further object of the present invention to provide a permutationlock assembly designed to fit conventional swinging doors to providemaximum security without the need of a key which could be lost, stolen,or duplicated.

It is a still further object of the present invention to provide acombined knob and permutation lock assembly for door latches whichrequires no additional preparation to a door beyond the normally drilledopenings for conventional hardware.

It is another object of the present invention to provide a combined knoband permutation lock assembly for door latches in which the combinationmay be readily changed.

It is still another object of the present invention to provide acombined knob and permutation lock assembly for door latchesincorporating a clutch device in the external knob that permits the knobto turn in either direction when the door is locked and excessive forceis applied, thus preventing damage to the assembly.

Another object of the present invention is the provision of a combinedknob and permutation lock assembly for door latches in which thecombination is selected by rotation of a single dial mounted coaxiallywith an external door knob.

Still other objects, features, and attendant advantages of the presentinvention will become apparent to those skilled in the art from areading of the following detailed description of the preferredembodiment constructed in accordance therewith, taken in conjunctionwith the accompanying drawings wherein like numerals designate likeparts in the several figures and wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the present combined knob andpermutation lock assembly for door latches as it appears connected to aconventional swinging door, using a conventional latch mechanism;

FIGS. 2, 3, and 5 are exploded, perspective views of portions of theassembly of FIG. 1;

FIG. 4 is a perspective view of the external rosette of the assembly ofFIG. 1;

FIG. 6 is a longitudinal, sectional view through the assembly of FIG. 1,taken in a vertical plane, with the lock assembly unlocked;

FIG. 7 is a sectional view taken along the line 7--7 in FIG. 6;

FIG. 8 is a sectional view taken along the line 8--8 in FIG. 6;

FIG. 9 is a sectional view taken along the line 9--9 in FIG. 6;

FIG. 10 is a sectional view taken along the line 10--10 in FIG. 6;

FIG. 11 is a sectional view similar to FIG. 6 with the lock assembly inthe locked position;

FIG. 12 is a sectional view taken along the line 12--12 in FIG. 11;

FIG. 13 is a partial, sectional view like FIG. 11 after the propercombination has been selected and the door knob has been rotated throughan angle of 90°;

FIG. 14 is a sectional view taken along the line 14--14 in FIG. 13; and

FIG. 15 is a partial, sectional view taken along the line 15--15 in FIG.14 showing the technique for changing the combination.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and, more particularly, to FIGS. 1-10 and12 thereof, the present combined knob and permutation lock assembly,generally designated 10, is designed for installation in a standardcircular hole 11 in a conventional door 12 to operate a conventionallatch mechanism 13. Latch mechanism 13 typically includes a pair ofplates 14 and 15 in which is mounted a slide member 16, movement ofwhich activates a latch tongue 17. Movement of slide member 16 iscontrolled by rotation of a shaft 18 having a generally C-shapedcross-section, extending through adjacent slots in plates 14 and 15 andslide member 16. Thus, rotation of shaft 18 in either direction causesone edge thereof to move slide member 16 to the left, as viewed in FIG.2, retracting tongue 17.

Shaft 18 is connected to a housing 19 which contains a spring 22, theopposite ends 20 and 21 of which extend outwardly from housing 19. Withends 20 and 21 restrained, as described more fully hereinafter, spring22 holds shaft 18 in its center position, as shown in FIG. 2, withtongue 17 extended. Thus, after rotation of shaft 18, as explained morefully hereinafter, by either of the door knobs and subsequent releasethereof, spring 22 will return shaft 18 to its center position,extending tongue 17.

Assembly 10 includes external and internal knobs 23 and 24,respectively, which are adapted to be mounted in coaxial relationship onopposite sides of door 12. Both knobs 23 and 24 are of conventional,conical shape, both knobs being hollow to contain portions of theactivating mechanisms of assembly 10. The inner end of knob 24 isexternally threaded, at 25, and extends through a central opening in aninternal rosette 26. Connection to internal rosette 26 is accomplishedthrough an internally threaded ring 27, which is tightened onto knob 24in such a manner as to permit the rotation of knob 24 relative torosette 26. Furthermore, and as shown most clearly in FIG. 10, the innerend of knob 24 has an arcuate slot 28 in the end thereof for receipt ofone end of shaft 18. Thus, rotation of knob 24 causes rotation of shaft18 and activation of latch mechanism 13, as described previously.

Extending through the center of knob 24 is a shaft 30, one end of whichis connected to a dial 31 positioned adjacent the external end of knob24. Connected to the inner end of shaft 30 is a radially outwardlyextending pin 32, the outer end of which engages a cam track 33 madeintegral with internal rosette 26. Thus, rotation of dial 31 and shaft30 causes pin 32 to move along track 33, causing axial movement of shaft30. With shaft 30 and dial 31 in the position shown in FIG. 6, dial 31is in its position farthest from door 12. On the other hand, clockwiserotation of dial 31 through an angle of 90° causes inward movement ofshaft 30 to the position shown in FIG. 11. Movement of dial 31 beyond90° is prevented by a pin 35 connected to rosette 26, at the end oftrack 33. When dial 31 is returned to the position shown in FIG. 6,shaft 30 is moved outwardly by means of a spring 34 positioned betweenknob 24 and shaft 30. As will be explained more fully hereinafter, it isthis rotation of dial 31 and axial movement of shaft 30 which is used tolock and unlock assembly 10 from the inside of door 12.

Assembly 10 includes a cam housing, generally designated 37, including acentral, elongate, hollow section 38, one end of which is connected toone end of a solid, reduced diameter section 39, the other end ofsection 39 having a serrated face 40. Extending from the center ofserrated face 40 is a reduced diameter, externally threaded section 41.Section 39 of housing 37 extends through the inner, hollow end of knob23 with section 41 positioned within knob 23. Mounted on threadedsection 41 is a clutch disc 42, one end of which has a serrated face 43which mates with serrated face 40 of cam housing 37. Clutch disc 42extends into a circular countersink 44 in the base of knob 23 androtation therebetween is prevented by means of a pair of pins 45, shownin FIG. 12, which intersect the circumferences of disc 42 andcountersink 44.

In order to maintain serrated faces 40 and 43 in contact, a nut 46 ismounted on the end of threaded section 41 of housing 37, a spring 47 anda pair of washers 48 at the opposite ends thereof being positionedbetween nut 46 and clutch disc 42. Accordingly, through the action ofspring 47 forcing clutch disc 42 against cam housing 37, rotation ofdoor knob 23 causes rotation of clutch disc 42, via pins 45, androtation of cam housing 37. The open, outer end of knob 23 is enclosed,after assembly, by a disc 49 which is press-fitted therein.

As shown most clearly in FIGS. 2, 6, and 9, the other end of centralsection 38 of cam housing 37 has a pair of collars 50 and 51 connectedthereto, collar 50 having a diameter greater than central section 38,and collar 51 having a diameter greater than collar 50. In the face ofcollar 51, opposite to the face connected to collar 50, is a pair ofgenerally C-shaped slots 52, one of which is adapted to receive one endof shaft 18, depending upon whether assembly 10 is positioned in a rightor a left-hand door. Thus, housing 37 completes the connection betweendoor knobs 23 and 24 in that one end of shaft 18 is connected in slot 28in knob 24 for rotation therewith, and the other end of shaft 18 isconnected in one of slots 52 in housing 37 which is connected to knob23, as described previously. Thus, shaft 18 and housing 37 define ashaft means extending coaxially between knobs 23 and 24 for rotationtherewith, such shaft means engaging and activating latch mechanism 13upon rotation thereof by either of knobs 23 or 24.

Central section 38 has a transverse hole therein, in which is mounted amovable pin 55. The base of pin 55 has a head 56 and a spring 57 ispositioned between head 56 and the inner wall of section 38, surroundingpin 55, to bias pin 55 downwardly, as viewed in FIG. 6. Pin 55 andspring 57 may be inserted into section 38 through a larger hole 58 insection 38, opposite hole 54. Once inserted into section 38, pin 55 andspring 57 are prevented from removal therefrom due to the insertion intosection 38 of a slide member 60. slide member 60 is in the nature of apin, one side of which is circular for contact with the cylindricalinner surface of section 38. The other side of slide member 60 has twoflat surfaces 61 and 62 connected by a cam surface 63, head 56 of pin 55being adapted to ride along surfaces 61-63. Slide member 60 movesaxially through section 38 and is prevented from rotation therein andremoval therefrom by a pin 64 which extends laterally therethrough andengages a pair of axial slots 65 on opposite sides of section 38 ofhousing 37.

Positioned within housing 37 is a spring 67 and a plunger 68 which arepositioned between one end of slide member 60, adjacent surface 61, andsection 39 of housing 37. Spring 67 and plunger 68 bias slide member 60to the right, as viewed in FIG. 6. In this position, head 56 of pin 55rests on surface 61, spring 57 retaining pin 55 in its retractedposition so that the outer end thereof does not extend beyond the outersurface of central section 38 of housing 37. On the other hand, withslide member 60 moved to the left, as viewed in FIG. 6, to the positionshown in FIG. 11, compressing spring 67, head 56 of pin 55 rides alongcam surface 63 to come to rest on surface 62, compressing spring 57 andextending the end of pin 55 beyond the outer surface of central section38 of housing 37.

Movement of slide member 60 is controlled by dial 31 and shaft 30. Thatis, slide member 60 has a shaft 69 made integral therewith which extendsthrough housing 19 and shaft 18 and rests against the end of shaft 30.With dial 31 and shaft 30 in the position shown in FIG. 6, spring 67 andplunger 68 move slide member 60 to the position shown in FIG. 6,retracting pin 55. With dial 31 and shaft 30 moved to the position shownin FIG. 11, shaft 69 is simultaneously moved to the left, as viewed inFIG. 11, compressing spring 67 and spring 57 and extending pin 55.

Assembly 10 further includes a lock sleeve 70 mounted on section 38 ofcam housing 37 for axial movement relative thereto. Lock sleeve 70 has apair of intersecting, diagonal slots 71 and 72 in the surface thereof,the intersection 73 of slots 71 and 72 being positioned directly abovehole 54 in section 38 of housing 37 when the component parts are in theposition shown in FIG. 6. Thus, when slide member 60 is moved to theposition shown in FIG. 11, the end of pin 55 extends into slots 71 and72. Since sleeve 70 is prevented from rotating, in a manner to bedescribed more fully hereinafter, rotation of cam housing 37 at thistime will cause movement of sleeve 70 towards collars 50 and 51 at theend of housing 37, due to the interaction of pin 55 and slot 71 or 72.On the other hand, with pin 55 retracted to the position shown in FIG.6, cam housing 37 can rotate totally independently of sleeve 70.

Lock sleeve 70 also includes a radially extending, generallyrectangular, planar key 75, whose function will be described more fullyhereinafter. Coplanar with key 75 and positioned above intersection 73and extending beyond the forward end of lock sleeve 70 is a bridgemember 76. Sleeve 70 is biased in the position shown in FIG. 6 by meansof a spring 77, one end of which contacts sleeve 70.

Assembly 10 further includes a base plate 80, one side 81 of which isadapted to contact the outside of door 12, as shown in FIG. 6, side 81of base plate 80 including a ring 82 which extends into hole 11 in door12 and centers the entire assembly 10. Extending axially from ring 82are two sets of pins 83 which retain spring ends 20 and 21 duringrotation of housing 19. Also extending axially from ring 82 are a pairof internally threaded barrels 84 which extend through hole 11 in door12, through holes in plates 14 and 15, and through slots in slide member16, into contact with a corresponding ring 85 connected to side 86 ofinternal rosette 26. A pair of semicircular sleeves 87 connected to ring85 surround the ends of barrels 84. A pair of holes 88 in internalrosette 26 are aligned with barrels 84. Thus, by extending a pair ofbolts 89 through holes 88 in internal rosette 26 and into barrels 84,base plate 80 and internal rosette 26 are secured to opposite sides ofdoor 12. All remaining components are connected either to internalrosette 26 or base plate 80.

The other side 91 of base plate 80 has a reduced diameter disc 92connected thereto, base plate 80 having a hole 93 extending entirelytherethrough. On side 91 of base plate 80 are first and secondcountersinks 94 and 95, countersink 94 receiving the other end of spring77. A small hole 96 extends axially through base plate 80, incountersink 95, along a vertical plane passing through the axis of baseplate 80, and a pair of holes 97 and 98 extend axially through baseplate 80, in countersink 95, along a horizontal plane passing throughthe axis of base plate 80. Extending radially inwardly into disc 92,from the outer circumference thereof, are a plurality of spaced holes99. Holes 99 extend only partially through disc 92 and receive springs100 and ball bearings 101, as shown most clearly in FIG. 8. Anadditional hole 99', which is coplanar with hole 96, extends all the wayto countersink 95 and receives a spring 102 and a lock pin 103. With theouter end of lock pin 103 tangent with the outer circumference of disc92, the inner end thereof is positioned immediately above hole 96. Theoperation of lock pin 103 will appear more fully hereinafter.

The permutation lock assembly portion of assembly 10 includes an outerdial cone 105, an inner dial cone 130 and locking rings 112 and 120.Outer dial cone 105 has a planar rear surface which contacts side 91 ofbase plate 80, surrounding disc 92. The rear portion 106 of dial cone105 has an internal diameter which is slightly larger than the diameterof disc 92 and has a serrated internal surface 107. As shown in FIG. 8,balls 101 contact serrations 107, causing cone 105 to assume one of afixed number of positions defined by serrations 107. Balls 101 alsocause a clicking sound as dial cone 105 is rotated relative to baseplate 80.

The forward portion 108 of dial cone 105 has a greater inside diameterthan portion 106 and has a serrated internal surface 109. Appearing onthe outer surface of dial cone 105 are a plurality of numbers, one foreach of serrations 107 and 109. In the present example, there are sixtyserrations 107 and 109 and sixty equally-spaced numbers, from 1 to 60,around the outside of dial cone 105. The desired number on dial cone 105may be selected by means of a mark 110 on the outer surface of baseplate 80.

Locking ring 112 has a plurality of radially inwardly extending holes113 in the circumference thereof, each of holes 113 receiving a spring114 and a ball 115. The outer diameter of locking ring 112 is slightlyless than the inner diameter of portion 108 of dial cone 105, andlocking ring 112 is positioned coaxially therewith so that balls 115engage serrations 109. Locking ring 112 also has a reduced diametercollar 116 extending from the side thereof, opposite from the sidecontacting portion 106 of dial cone 105. A radially extending, generallyrectangular, slot 117 extends through collar 116 and partially intolocking ring 112.

Locking ring 120 has an inside diameter approximately equal to the outerdiameter of collar 116, a thickness equal to the thickness of collar116, and an outer diameter which is less than the outer diameter oflocking ring 112. Locking ring 120 also has a plurality of radiallyinwardly extending holes 121 in the circumference thereof, each of holes121 receiving a spring 122 and a ball 123. Locking ring 120 also has aradially extending, generally rectangular, slot 124 therein, slot 124being adapted to be aligned with slot 117 in collar 116 and having adepth equal to the depth of the slot in locking ring 112.

Inner dial cone 130 has an inside diameter which is slightly greaterthan the outside diameter of locking ring 120 and serrated internalsurface 131. Inner dial one 130 is adapted to be mounted coaxially withouter dial cone 105, with the rear surface thereof engaging one face oflocking ring 112 and with balls 123 in locking ring 120 extending intoserrations 131. The outwardly directed face of inner dial cone 130 has aplurality of numbers thereon, one for each of serrations 131. In thepresent example, there are sixty serrations in dial cone 130 and thenumbers 1 through 60 appear on the outer face thereof.

While the major portion of the outer surface of dial cone 130 isconical, the rear end 132 is cylindrical and has a slot 133 therein. Asshown most clearly in FIG. 7, slot 133 houses a ratchet mechanismincluding a pawl 134 mounted for rotation on a pin 135 and being biasedby a spring 136. Spring 136 urges pawl 134 outwardly into contact withserrations 109 on the inner surface of portion 108 of dial cone 105. Asdial cone 105 is rotated in a clockwise direction, as viewed in FIG. 7,pawl 134 is held in serrations 109, causing inner dial cone 130 torotate with outer dial cone 105. On the other hand, when outer dial cone105 is rotated in a counterclockwise direction, as viewed in FIG. 7,spring 136 compresses, permitting pawl 134 to be retracted fromserrations 109, skipping from serration to serration and permittinginner dial cone 130 to remain stationary during rotation of outer dialcone 105.

The last major component of assembly 10 is the external rosette 140.External rosette 140 includes a cylindrical section 141 having an axialhole 142 extending entirely therethrough, hole 142 terminating in a lip143 and then a countersink 144 at one end thereof. Countersink 144receives the inner end of knob 23, whereas lip 143 contains sleeve 70,which is movable through hole 142, and the lip at the intersectionbetween portions 38 and 39 of cam housing 37, which is rotatable in hole142. Extending from the other end of cylindrical section 141 of externalrosette 140 is a sleeve 145 which has an inside diameter equal to theinside diameter of hole 142 and an outside diameter which is slightlyless than the inside diameter of locking ring 112. Sleeve 145 extendsthrough locking ring 112 with the inner face of cylindrical section 141contacting collar 116 and locking ring 120. The free end of sleeve 145extends countersink 95 in base plate 80 and has a pair of internallythreaded, axial holes 146 and 147 therein which align with holes 97 and98, respectively, in base plate 80. Thus, by extending a pair of bolts148 and 150 through holes 97 and 98, respectively, in base plate 80 andinto threaded holes 146 and 147, respectively, in sleeve 145, externalrosette 140 is rigidly connected to base plate 80.

As stated previously, lock sleeve 70 is contained within sleeve 145 ofexternal rosette 140 and moves therethrough between the positions shownin FIGS. 6 and 13, as will be described more fully hereinafter. Sleeve145 has a slot 149 in the top thereof that extends for the entire lengththereof for receipt of key 75 of lock sleeve 70. Slot 149 also extendspartially into cylindrical section 141, again to receive key 75. Theouter circumference of cylindrical section 141 of rosette 140 has aplurality of radially inwardly extending holes 151 therein, each hole151 receiving a spring 152 and a ball 153, balls 153 engaging serrations131 of inner dial cone 130.

External rosette 140 includes a hollow, conical section 154 whichextends from the end of cylindrical section 141 adjacent countersink144. The outer surface of conical section 154 represents an extension ofthe outer surface of outer dial cone 105, and the inner surface hasdimensions approximately equal to the outer conical surface of innerdial cone 130. Conical section 154 has a window 155 therein, throughwhich the numbers on inner dial cone 130 may be viewed. A magnifyinglens 156, mounted in window 155, may be used for enlargement of thenumbers along inner dial cone 130. A hairline 157 on lens 156 may beused to locate a desired number on inner dial cone 130.

As part of the mechanism for changing the combination of the permutationmechanism of assembly 10, internal rosette 26, base plate 80, andlocking ring 112 have alignable holes 29, 90, and 118 extending entirelytherethrough, and locking ring 120 has an alignable hole 125 extendingpartially therethrough. A removable pin-key 160 is insertable throughhole 29 in internal rosette 26 and through hole 90 in base plate 80,holes 29 and 90 always being aligned, and into holes 118 and 125 inlocking rings 120 and 112, respectively, under certain circumstances, tobe described more fully hereinafter.

OPERATION

FIGS. 6, 7, and 8 show assembly 10 unlocked from the inside thereof. Tounlock the door from the inside, plunger dial 31 is rotatedcounterclockwise, simultaneously traveling outwardly approximately 3/8inches as it rotates 90°, pin 32 moving along cam track 33 and spring 34moving shaft 30 to the right, as viewed in FIG. 6. As shaft 30 moves tothe right, it permits spring 67 and plunger 68 to move slide member 60in the same direction, due to the contact between shaft 69 and shaft 30.As slide member 60 travels with shafts 69 and 30, head 56 of pin 55moves to surface 61 on slide member 60, spring 57 causing pin 55 to bewithdrawn into housing 37.

With assembly 10 in this unlocked position, latch mechanism 13 can bemanipulated to retract tongue 17 by turning either the external knob 23or internal knob 24 in either direction. Rotation of external knob 23rotates shaft 18 through the intermediary of cam housing 37, whereasinternal knob 24 rotates shaft 18 directly.

Locking the door is accomplished by turning dial 31 mounted withininternal door knob 24 in a clockwise direction through an angle of 90°to the position shown in FIG. 11. As dial 31 rotates, it travelsinwardly as pin 32 travels along cam track 33. As shaft 30 movesinwardly, it forces shaft 69 and slide member 60 forwardly, causing head56 of pin 55 to travel from surface 61 to surface 62 via cam surface 63.This action simultaneously compresses springs 57 and 67 and pin 54 nowextends beyond the outer surface of section 38 of housing 37 into slots71 and 72, at intersection 73, in lock sleeve 70. With lock assembly 10in the above-described locked position and the assembly not programed toopen, latch mechanism 13 cannot be operated. That is, external knob 23is attached to cam slide housing 37 through the intermediary of pins 45and clutch disc 42. As knob 23 turns, so does housing 37, thus biasingin an axially inward direction lock sleeve 70. If door 12 is notprogramed to open, this action will move lock sleeve key 75, which isattached securely to sleeve 70, flush against collar 116 of locking ring112 and/or locking ring 120. Since lock sleeve 70 cannot move forwardly,cam housing 37 cannot rotate, preventing any further motion of door knob23 and preventing activation of latch mechanism 13 and retraction oftongue 17.

Excessive pressure on external door knob 23 will allow knob 23 to rotatewithout retracting latch tongue 17 or permitting damage to be incurredto any part of assembly 10. This is accomplished through the attachmentof clutch disc 42, which is mounted in knob 23. The serrated face 43 ofclutch disc 42 meshes with the serrated face 40 at the end of section 39of housing 37 and is held snugly in position by the pressure of spring47. However, excessive pressure on knob 23 forces serrations 40 and 43to slip passed each other, causing clutch disc 42 and knob 23 to retractaxially relative to housing 37, compressing spring 47. This permits knob23 and disc 42 to rotate without rotating housing 37.

With dial 31 in the position shown in FIG. 11 and mechanism 10 locked,latch mechanism 13 may be activated by selection of the propercombination as follows. Considering FIGS. 6, 7, and 8, rotation of outerdial cone 105 clockwise in turn forces the rotation of inner dial cone130, due to the previously described interaction between pawl 134 andserrations 109 in dial cone 105. By looking at the indicia on inner dialcone 130 through lens 156, inner dial cone 130 may be rotated in aclockwise direction until the programed number comes in alignment withhairline 157 on lens 156. Simultaneously with the rotation of inner dialcone 130, locking ring 120 is being rotated. This occurs because balls123 are held by springs 122 in serrations 131 of inner dial cone 130.Furthermore, when the programed number on inner dial cone 130 is inalignment with hairline 157, slot 124 in locking ring 120 is alignedwith lock sleeve key 75.

Outer dial cone 105 may now be turned in a counterclockwise directionuntil the programed number appears in alignment with mark 110 at the topof base plate 80. When outer dial cone 105 is rotated in acounterclockwise direction, pawl 134 compresses spring 136, permittinginner dial cone 130 to remain stationary. Furthermore, springs 152 urgeballs 153 in external rosette 140 into serrations 131 of inner dial cone130, holding inner dial cone 130 stationary as outer dial cone 105rotates. Since locking ring 120 is coupled to inner dial cone 130 bymeans of springs 122 and balls 123, locking ring 120 will also remainstationary at this time.

On the other hand, locking ring 112 will rotate with outer dial cone105. That is, springs 114 hold balls 115 in serrations 109 in portion108 of outer dial cone 105 so that locking ring 112 is caused to rotatewith outer dial cone 105. Rotating outer dial 110 on base plate 80brings slot 117 into alignment with slot 124 and into alignment withlock sleeve key 75. This position is shown in FIGS. 13 and 14 androtation of knob 23 is now permitted. That is, as knob 23 is rotated,rotating cam housing 37, pin 55, extending into one of slots 71 or 72 inlock sleeve 71, will cause axially inward movement of lock sleeve 70.Since slots 117 and 124 in lock rings 112 and 120, respectively, are nowaligned with lock sleeve key 75, lock sleeve key 75 moves forwardly tothe position shown in FIG. 13, entering slots 117 and 124. This actionpermits rotation of knob 23, cam housing 37, and shaft 18, therebyactivating latch mechanism 13 and retracting tongue 17.

Bridge member 76 connected to lock sleeve 70 is designed to prevent therecession of lock pin 103 when knob 23 is slightly turned, whetherassembly 10 is in a locked to unlocked position. That is, when lock pin55 causes forward movement of lock sleeve 70, bridge member 76 movesinto position beneath lock pin 103, as shown in FIG. 13, and eventuallyinto hole 96 in base plate 80. With bridge member 76 in this position,lock pin 103 cannot be retracted and remains engaged with serrations 107in portion 106 of outer dial cone 105. This eliminates the accidentalchanging of the combination. Normally, lock pin 103 is under springpressure, with spring 102 forcing the upper end thereof to mesh withserrations 107 of outer dial cone 105. This achieves an indexingfunction and a clicking sound during rotation of outer dial cone 105, asexplained previously.

To change the combination, it is first necessary to know the existingcombination. That is, when locking rings 112 and 120 are in thepositions shown in FIG. 14, all of holes 29, 90, 118, and 125 arealigned. At this time pin-key 160 can be inserted through hole 29 ininternal rosette 26, which permits key 160 to travel through internalrosette 26, through hole 90 in base plate 80, and to come to rest withinholes 118 and 125 in locking rings 112 and 120, respectively. Withpin-key 160 in this position, locking rings 112 and 120 are preventedfrom rotating. Thus, outer dial cone 105 can be rotated clockwise and,in so doing, will rotate inner dial cone 130, as described previously,to whatever new number is desired. Then, outer dial cone 105 can berotated counterclockwise to whatever new number is desired for it, innerdial cone 130 remaining stationary at this time. During the rotation ofouter and inner dial cones 105 and 130, respectively, locking rings 112and 120 are held stationary, keeping slots 117 and 124, respectivelytherein, aligned with lock sleeve key 75. In addition, springs 114 and122 compress, permitting balls 115 and 123, respectively, to slip alongserrations 109 and 131, respectively, so that dial cones 105 and 130rotate independently of locking rings 112 and 120. Now, extractingpin-key 160, the lock has been newly programed and continued rotation ofouter dial cone 105 will manipulate inner dial cone 130 and lockingrings 112 and 120, as explained previously.

It can therefore be seen that according to the present invention, thereis provided a combined knob and permutation lock assembly 10 foroperating door latch mechanism 13 which is designed to fit conventionalswinging doors to provide maximum security without the need of a keywhich could be lost, stolen, or duplicated. With assembly 10, there isno need to prepare door 12 beyond the normally drilled openings forconventional hardware. Once installed, external door knob 23 haspositioned adjacent thereto a coaxial dial cone 105, which may berotated first in one direction and then in another direction to dial adesired combination. With sixty numbers on dial cones 105 and 130, 3,540combinations are available. Furthermore, assembly 10 permits anoperator, when the proper combination is known, to change within amatter of seconds from one combination to another, thereby eliminatingthe expensive re-keying process normally associated with key-activatedlocks.

When assembly 10 is locked and knob 23 is attempted to be turned, tongue17 will not retract. Also incorporated is a clutch device includingclutch disc 42 which permits knob 23 to turn in either direction whenthe door is locked and excessive force is applied thereto, thuspreventing damage to assembly 10.

Assembly 10 offers outstanding visibility of the characters on dials 105and 130, with dial cone 105 controlling hidden dial 130. Thus, assembly10 can be programed to open very rapidly with the use of one handrotating outer dial 105 in one direction, which rotates inner dial cone130 which is visible through magnifying lens 156. Then, by rotatingouter dial cone 105 in the other direction until the proper number isaligned with mark 110, assembly 10 is unlocked. Locking assembly 10 isachieved by simply rotating through an angle of 90° dial plunger 31mounted within internal knob 24.

While the invention has been described with respect to a preferredphysical embodiment constructed in accordance therewith, it will beapparent to those skilled in the art that various modifications andimprovements may be made without departing from the scope and spirit ofthe invention. For example, any number of serrations may be utilized indial cones 105 and 130 to adjust the different number of combinationsavailable. Furthermore, by adding a third dial cone, which would beindependently rotatable and control an independently rotatable lockingring, the number of combinations could be increased. With sixty numberson three dials, there would be 216,000 different combinations.Alternatively, by placing on each dial the alphabet, rather thannumbers, there would be permitted the spelling of any three-letter wordwith just under 20,000 various combinations. Accordingly, it is to beunderstood that the invention is not to be limited by the specificillustrative embodiment, but only by the scope of the appended claims.

I claim:
 1. A combination knob and permutation lock assembly adapted tobe mounted in a door for controlling a door latch comprising:coaxialexternal and internal knobs mounted for rotation on opposite sides ofsaid door; shaft means extending coaxially between said door knobs forrotation therewith, said shaft means engaging and activating said doorlatch upon rotation thereof by either of said knobs; sleeve meansmounted on said shaft means for axial movement only relative to saidassembly, said sleeve means having a diagonal slot therein and includinga radially extending key; a pin mounted within said shaft means andbeing movable axially relative thereto, perpendicular to the axis ofsaid shaft means, into and out of said slot in said sleeve means, saidshaft means being rotatable to activate said door latch independently ofsaid sleeve means when said pin is withdrawn from said slot in saidsleeve means, rotation of said shaft means causing axial movement ofsaid sleeve means when said pin is extending into said slot therein;means for biasing said pin out of said slot in said sleeve means;manually operable cam means for moving said pin into said slot in saidsleeve means to thereby lock said door; first and second locking ringsmounted coaxially with said shaft means, said locking rings having firstand second slot means therein, respectively, alignable with said sleevemeans key, said locking rings preventing axial movement of said sleevemeans and activation of said door latch except when both said first andsecond slot means are aligned with said sleeve means key; and meansmounted coaxially with and adjacent said external door knob andoperatively connected to said first and second locking rings forindependently moving said locking rings to align said first and secondslot means with said sleeve means key so as to unlock said assembly. 2.An assembly according to claim 1 wherein said first and second lockingrings are coplanar, said first and second slot means defining acontinuous slot when aligned.
 3. An assembly according to claim 1wherein said shaft means comprises:an elongate, generally cylindrical,hollow section having a transverse hole therein, said pin being mountedfor axial movement in said hole in said hollow section.
 4. An assemblyaccording to claim 3 wherein said pin has a head at the end thereoffarthest from said hole in said hollow section and wherein said pinbiasing means comprises:a spring surrounding said pin and extendingbetween said head and the inner wall of said hollow section.
 5. Anassembly according to claim 4 wherein said cam means comprises:a slidemember mounted within said hollow section of said shaft means, saidslide member having a cam surface, said head of said pin resting on saidcam surface of said slide member, said slide member being axiallymovable in said hollow section of said shaft means, said cam surface ofsaid slide member moving said pin through said hole into and out of saidslot in said sleeve means as said slide member moves axially; and secondshaft means extending through said hollow section of saidfirst-mentioned shaft means and connected between said slide member andsaid internal knob for manually moving said slide member from a positionadjacent said internal knob.
 6. An assembly according to claim 5 whereinsaid cam means further comprises:third shaft means mounted for rotationin said internal knob, one end of said third shaft means contacting oneend of said second shaft means; a dial connected to the other end ofsaid third shaft means and positioned approximately coplanar with theexternal end of said internal knob; and cam means operatively connectedto said third shaft means for causing axial movement of said third shaftmeans upon rotation thereof, whereby rotation of said dial rotates saidthird shaft means, moving said third shaft means, said second shaftmeans, and said slide member axially, causing locking and unlocking ofsaid assembly.
 7. An assembly according to claim 1 wherein said sleevemeans has first and second intersecting, oppositely extending, diagonalslots therein, said cam means moving said pin into the intersection ofsaid slots in said sleeve means, whereby rotation of said shaft means ineither direction causes axial movement of said sleeve means along saidshaft means.
 8. An assembly according to claim 7 wherein said first andsecond locking rings are coplanar, said first and second slot meansdefining a continuous slot when aligned, said sleeve means key enteringsaid continuous slot when said first and second slot means are alignedwith said sleeve means key, movement of said sleeve means beingprevented when either said first of said second slot means aremisaligned with said sleeve means key.
 9. An assembly according to claim1 wherein said means for moving said locking rings comprises:outer andinner concentric dials mounted adjacent said external door knob andhaving indicia on the outwardly directed faces thereof; meansinterconnecting said dials for rotation of said inner dial with saidouter dial in a first rotary direction only; means operativelyconnecting said first locking ring to said outer dial; and meansoperatively connecting said second locking ring to said inner dial forrotation therewith, said outer dial being rotatable in said firstdirection, thereby rotating said inner dial and said first and secondlocking rings, to align said second slot means in said second lockingring with said sleeve means key, said outer dial being rotatable in anopposite rotary direction, thereby rotating said first locking ring, toalign said first slot means in said first locking ring with said secondslot means and said sleeve means key, said inner dial and said secondlocking ring remaining stationary during rotation of said outer dial andsaid first locking ring in said opposite direction.
 10. An assemblyaccording to claim 9 wherein each of said dials has an internallyserrated surface and wherein said means connecting said locking rings tosaid dials comprises:spring-biased ball bearings mounted in the outercircumferences of said locking rings, said balls engaging said serratedsurfaces of said dials.
 11. An assembly according to claim 10 whereinsaid locking rings have axially directed holes therein, said holes beingaligned when said first and second slot means are aligned, and furthercomprising:a pin extendable through said aligned holes in said lockingrings for holding said locking rings stationary during rotation of saidouter and inner concentric dials to permit changing of the combinationof said assembly.
 12. An assembly according to claim 10 wherein saidmeans interconnecting said dials comprises:a ratchet mechanism includinga spring-biased pawl connected to said inner dial, said pawl engagingsaid internally serrated surface of said outer dial, said ratchetmechanism forcing said inner dial to rotate with said outer dial whensaid outer dial is rotated in said first rotary direction, said ratchetmechanism causing slipping between said pawl and said internallyserrated surface of said outer dial when said outer dial is rotated insaid opposite direction.
 13. An assembly according to claim 1 furthercomprising:friction clutch means connecting said external knob to saidshaft means, said clutch means permitting independent rotation of saidexternal knob and said shaft means when said assembly is locked.
 14. Anassembly according to claim 13 wherein said clutch means comprises:aserrated face on said shaft means; a clutch disc having a serrated facewhich mates with said shaft means serrated face; means for connectingsaid clutch disc to said external knob for rotation therewith andlimited axial movement relative thereto; and means connected to saidshaft means for biasing said clutch disc serrated face into contact withsaid shaft means serrated face, said biasing means normally exerting asufficient force to prevent slippage between said serrated faces,excessive force on said external knob causing slippage of said serratefaces and rotation of said external knob independently of said shaftmeans.
 15. A combination knob and permutation lock assembly adapted tobe mounted in a door for controlling a door latch comprising:coaxialexternal and internal knobs mounted for rotation on opposite sides ofsaid door; shaft means extending coaxially between said door knobs forrotation therewith, said shaft means engaging and activating said doorlatch upon rotation thereof by either of said knobs; sleeve meansmounted on said shaft means for axial movement only relative to saidassembly as said shaft means is rotated by either said external or saidinternal knob, said sleeve means including a radially extending key;first and second coplanar locking rings mounted coaxially with saidshaft means, said locking rings having first and second slot meanstherein, respectively, alignable with each other to define a continuousslot which is alignable with said sleeve means key, said locking ringspreventing axial movement of said sleeve means and activation of saiddoor latch except when both said first and second slot means are alignedwith said sleeve means key; and means mounted coaxially with andadjacent said external door knob and operatively connected to said firstand second locking rings for independently moving said locking rings toalign said first and second slot means with said sleeve means key so asto unlock said assembly.
 16. An assembly according to claim 15 whereinsaid means for moving said locking rings comprises:outer and innerconcentric dials mounted adjacent said external door knob and havingindicia on the outwardly directed faces thereof; means interconnectingsaid dials for rotation of said inner dial with said outer dial in afirst rotary direction only; means operatively connecting said firstlocking ring to said outer dial; and means operatively connecting saidsecond locking ring to said inner dial for rotation therewith, saidouter dial being rotatable in said first direction, thereby rotatingsaid inner dial and said first and second locking rings, to align saidsecond slot means in said second locking ring with said sleeve meanskey, said outer dial being rotatable in an opposite rotary direction,thereby rotating said first locking ring, to align said first slot meansin said first locking ring with said second slot means and said sleevemeans key, said inner dial and said second locking ring remainingstationary during rotation of said outer dial and said first lockingring in said opposite direction.
 17. An assembly according to claim 16wherein each of said dials has an internally serrated surface andwherein said means connecting said locking rings to said dialscomprises:spring-biased ball bearings mounted in the outercircumferences of said locking rings, said balls engaging said serratedsurfaces of said dials.
 18. An assembly according to claim 17 whereinsaid means interconnecting said dials comprises:a ratchet mechanismincluding a spring-biased pawl connected to said inner dial, said pawlengaging said internally serrated surface of said outer dial, saidratchet mechanism forcing said inner dial to rotate with said outer dialwhen said outer dial is rotated in said first rotary direction, saidratchet mechanism causing slipping between said pawl and said internallyserrated surface of said outer dial when said outer dial is rotated insaid opposite direction.
 19. An assembly according to claim 16 furthercomprising:a face plate mounted concentrically with said dials, adjacentsaid external door knob, said inner dial being hidden behind said faceplate, said face plate having a window therein for viewing said indiciaon said inner dial therethrough.